NAME

imapfilter_config - imapfilter configuration file

SYNOPSIS

$HOME/.imapfilter/config.lua

DESCRIPTION

imapfilter(1) uses the Lua programming language (http://www.lua.org) as a
configuration and extension language, therefore the configuration file is
a Lua script.
Although knowledge of Lua is not required to use imapfilter(1), it is
nonetheless recommended, especially if one wants to extend imapfilter(1).
The user is advised to have a look at the available Lua documentation at:
http://www.lua.org/docs.html

CONVENTIONS

A brief description of the Lua values and types mentioned hereafter in
the manual page follows:
The nil is the type of the value ‘‘nil’’ , whose main property is to
be different from any other value; usually it represents the absence
of a useful value.
The boolean is the type of the values ‘‘true’’ and ‘‘false’’. Both
‘‘nil’’ and ‘‘false’’ make a condition false; any other value makes
it true.
The type number represents real numbers.
The type string represents a sequence of characters and can be
defined using single quotes, double quotes or double square brackets.
The type table implements associative arrays, that is, arrays that
can be indexed not only with numbers, but with any value.
A function is a first-class value; it can be stored in variables,
passed as argument to other functions, and returned as a result.

OPTIONS

Program’s options are set using an already initialised table named
‘‘options’’ , in the following manner:
options.timeout = 120
options.namespace = false
Available options are:
create According to the IMAP specification, when trying to write a
message to a non-existent mailbox, the server must send a hint to
the client, whether it should create the mailbox and try again or
not. However some broken IMAP servers don’t follow the
specification and don’t send the correct response code to the
client. By enabling this option the client tries to create the
mailbox, despite of the server’s response. This variable takes a
boolean as a value. Default is ‘‘false’’.
close This option controls whether the currently selected mailbox is
implicitly closed at the end of each performed operation, thus
removing all messages that are marked deleted. This variable
takes a boolean as a value. Default is ‘‘false’’.
crammd5
When this option is enabled and the server supports the
Challenge-Response Authentication Mechanism (specifically CRAM-
MD5), this method will be used for user authentication instead of
a plaintext password LOGIN. This variable takes a boolean as a
value. Default is ‘‘true’’.
expunge
Normally, messages are marked for deletion and are actually
deleted when the mailbox is closed. When this option is enabled,
messages are expunged immediately after being marked deleted.
This variable takes a boolean as a value. Default is ‘‘true’’.
info When this options is enabled, a summary of the program’s actions
is printed, while processing mailboxes. This variable takes a
boolean as a value. Default is ‘‘true’’.
namespace
When enabled, the program gets the namespace of the user’s
personal mailboxes, and applies automatically the prefix and
hierarchy delimiter to any mailboxes residing on the mail server;
the user must use the ‘/’ character as the delimiter and ‘‘’’
(ie. nothing) as the prefix, regardless of the folder format of
the mail server. This must be disabled, if the user wants to
manually specify mailbox names (eg. because they are not part of
the user’s personal namespace mailboxes). This variable takes
boolean as a value. Default is ‘‘true’’.
starttls
When this option is enabled and the server supports the IMAP
STARTTLS extension, a TLS connection will be negotiated with the
mail server in the beginning of the session. This variable takes
a boolean as value. Default is ‘‘true’’.
subscribe
By enabling this option new mailboxes that were automatically
created, get also subscribed; they are set active in order for
IMAP clients to recognize them. This variable takes a boolean as
a value. Default is ‘‘false’’.
timeout
The time in seconds for the program to wait for a mail server’s
response. If not set, the client will block indefinitely. This
variable takes a number as a value.

ACCOUNT

Accounts are initialized using the IMAP() function, and the details of
the connection are defined using an account table:
myaccount = IMAP {
server = ’imap.mail.server’,
username = ’me’,
password = ’secret’,
ssl = ’ssl3’
}
An account table must have the following elements:
server The hostname of the IMAP server to connect to. It takes a string
as a value.
username
User’s name. It takes a string as a value.
An account table can also have the following optional elements:
password
User’s secret keyword. If a password wasn’t supplied the user
will be asked to enter one interactively the first time it will
be needed. It takes a string as a value.
port The port to connect to. It takes a number as a value. Default
is ‘‘143’’ for imap and ‘‘993’’ for imaps.
ssl Forces an imaps connection and specifies the SSL/TLS protocol to
be used. It takes a string as a value, specifically one of:
‘‘ssl2’’ , ‘‘ssl3’’ , ‘‘tls1’’.
LISTING
The following methods can be used on an account to list mailboxes in a
folder of an account:
list_all(folder)
Lists all the available mailboxes in the folder (string), and
returns a table that contains strings, the available mailboxes,
and a table that contains strings, the available folders.
list_subscribed(folder)
Lists all the subscribed mailboxes in the folder (string), and
returns a table that contains strings, the subscribed mailboxes,
and a table that contains strings, the subscribed folders.
The following methods can be used on an account to list mailboxes, using
wildcards, in a folder of an account. The ‘*’ wildcard, matches any
character and the ‘%’ matches any character except the folder delimiter,
ie. non-recursively:
list_all(folder, mailbox)
Lists all the available mailboxes in the folder (string) with the
name mailbox (string), and returns a table that contains strings,
the available mailboxes, and a table that contains strings, the
available folders. Wildcards may only be used in the mailbox
argument.
list_subscribed(folder, mailbox)
Lists all the subscribed mailboxes in the folder (string) with
the name mailbox (string), and returns a table that contains
strings, the subscribed mailboxes, and a table that contains
strings, the subscribed folders. Wildcards may only be used in
the mailbox argument.
Examples:
mailboxes, folders = myaccount:list_subscribed(’myfolder’)
mailboxes, folders = myaccount:list_all(’myfolder/mysubfolder’, ’*’)
MANIPULATING
The following methods can be used to manipulate mailboxes in an account:
create_mailbox(name)
Creates the name (string) mailbox.
delete_mailbox(name)
Deletes the name (string) mailbox.
rename_mailbox(oldname, newname)
Renames the oldname (string) mailbox to newname (string).
subscribe_mailbox(name)
Subscribes the name (string) mailbox.
unsubscribe_mailbox(name)
Unsubscribes the name (string) mailbox.
Examples:
myaccount:create_mailbox(’mymailbox’)
myaccount:subscribe_mailbox(’mymailbox’)
myaccount:unsubscribe_mailbox(’myfolder/mymailbox’)
myaccount:delete_mailbox(’myfolder/mymailbox’)

MAILBOX

After an IMAP account has been initialized, mailboxes residing in that
account can be accessed simply as elements of the account table:
myaccount.mymailbox
If mailbox names don’t only include letters, digits and underscores, or
begin with a digit, an alternative form must be used:
myaccount[’mymailbox’]
A mailbox inside a folder can be only accessed by using the alternative
form:
myaccount[’myfolder/mymailbox’]
The methods that are available for an account (eg. list_all(),
create_mailbox(), etc.) , are considered keywords and must not be used as
mailbox names, and the same also applies for any string starting with an
underscore, as they are considered reserved.
CHECKING
The following methods can be used to check the status of a mailbox:
check_status()
The check_status() method gets the current status of a mailbox,
and returns three values of number type: the total number of
messages, the number of recent messages and the number of unseen
messages in the mailbox.
exist, unread, unseen = myaccount.mymailbox:check_status()
SEARCHING
All the searching methods in this subsection return a special form of
table. This table can be combined with other tables using logic theory.
There are three available operations, that implement logical ‘‘or’’,
logical ‘‘and’’ and logical ‘‘not’’.
The logical ‘‘or’’ is implemented using the ‘+’ operator:
messages = myaccount.mymailbox:is_unseen() +
myaccount.mymailbox:is_larger(100000)
The logical ‘‘and’’ is implemented using the ‘*’ operator:
messages = myaccount.mymailbox:is_unseen() *
myaccount.mymailbox:is_larger(100000)
The logical ‘‘not’’ is implemented using the ‘-’ operator:
messages = myaccount.mymailbox:is_unseen() -
myaccount.mymailbox:is_larger(100000)
The three logical operators can be combined in the same expression. The
logical ‘‘and’’ has higher precedence than the logical ‘‘or’’ and the
logical ‘‘not’’, with the latter two having the same precedence, and
parentheses may be used to change this behaviour:
messages = myaccount.mymailbox:is_unseen() +
myaccount.mymailbox:is_larger(100000) *
myaccount.mymailbox:contain_subject(’test’)
messages = ( myaccount.mymailbox:is_unseen() +
myaccount.mymailbox:is_larger(100000) ) *
myaccount.mymailbox:contain_subject(’test’)
The returned tables of the searching methods can also be stored in
variables and then further processed:
unseen = myaccount.myaccount:is_unseen()
larger = myaccount.mymailbox:is_larger(100000)
subject = myaccount.mymailbox:contain_subject(’test’)
messages = unseen + larger * subject
A composite filter that includes one or more simple rules can be defined:
myfilter = function ()
return myaccount.mymailbox:is_unseen() +
myaccount.mymailbox:is_larger(100000) *
myaccount.mymailbox:contain_subject(’test’)
end
messages = myfilter()
Composite filters can may be more dynamic by adding arguments:
myfilter = function (mailbox, size, subject)
return mailbox:is_unseen() +
mailbox:is_larger(size) *
mailbox:contain_subject(subject)
end
messages = myfilter(myaccount.mailbox, 100000, ’test’)
The following methods can be used to search for messages that are in a
specific state:
is_answered()
Messages that have been answered.
is_deleted()
Messages that are marked for later removal.
is_draft()
Messages that have not completed composition.
is_flagged()
Messages that are flagged for urgent/special attention.
is_new()
Messages that are recently arrived (this session is the first to
have been notified about these messages) and have not been read.
is_old()
Messages that are not recently arrived (this session is not the
first to have been notified about these messages) and have not
been read.
is_recent()
Messages that are recently arrived (this session is not the first
to have been notified about these messages).
is_seen()
Messages that have been read.
is_unanswered()
Messages that have not been answered.
is_undeleted()
Messages that are not marked for later removal.
is_undraft()
Messages that have completed composition.
is_unflagged()
Messages that are not flagged for urgent/special attention.
is_unseen()
Messages that have not been read.
The following method can be used to search for messages that have a
specific flag set:
has_flag(keyword)
Messages with the specified keyword flag (string) set.
The following methods can be used to search for messages based on their
size:
is_larger(size)
Messages that are larger than the size (number) in octets
(bytes).
is_smaller(size)
Messages that are smaller than the size (number) in octets
(bytes).
The following methods can be used to search for messages based on their
age:
is_newer(age)
Messages that are newer than the age (number) in days.
is_older(age)
Messages that are older than the age (number) in days.
The following methods can be used to search for messages based on their
arrival or sent date, in the ‘‘day-month-year’’ form, where day is the
day of the month as a decimal number (01-31), month is the abbreviated
month (‘‘Jan’’, ‘‘Feb’’, ‘‘Mar’’, ‘‘Apr’’, ‘‘May’’, ‘‘Jun’’, ‘‘Jul’’,
‘‘Aug’’, ‘‘Sep’’, ‘‘Oct’’, ‘‘Nov’’, ‘‘Dec’’) and year is the year as
decimal number including the century (eg. 2007):
arrived_before(date)
messages that have arrived before the date (string), where date
is in the ‘‘day-month-year’’ form.
arrived_on(date)
Messages that have arrived on the date (string), where date is in
the ‘‘day-month-year’’ form.
arrived_since(date)
Messages that have arrived after the date (string), where date is
in the ‘‘day-month-year’’ form.
sent_before(date)
Messages that have been sent before the date (string), where date
is in the ‘‘day-month-year’’ form.
sent_on(date)
Messages that have been sent on the date (string), where date is
in the ‘‘day-month-year’’ form.
sent_since(date)
Messages that have been sent after the date (string), where date
is in the ‘‘day-month-year’’ form.
The following methods can be used to search for messages that contain a
specific word or phrase:
contain_bcc(string)
Messages that contain the string (string) in the ‘‘Bcc’’ header
field.
contain_cc(string)
Messages that contain the string (string) in the ‘‘Cc’’ header
field.
contain_from(string)
Messages that contain the string (string) in the ‘‘From’’ header
field.
contain_subject(string)
Messages that contain the string (string) in the ‘‘Subject’’
header field.
contain_to(string)
Messages that contain the string (string) in the ‘‘To’’ header
field.
contain_field(field, string)
Messages that contain the string (string) in the field (string)
header field.
contain_header(string)
Messages that contain the string (string) in the message header.
contain_body(string)
Messages that contain the string (string) in the message body.
contain_message(string)
Messages that contain the string (string) in the message.
The following methods can be used to search for messages that match a
specific regular expression pattern:
match_bcc(pattern)
Messages that match the regular expression pattern (string) in
the ‘‘Bcc’’ header field.
match_cc(pattern)
Messages that match the regular expression pattern (string) in
the ‘‘Cc’’ header field.
match_from(pattern)
Messages that match the regular expression pattern (string) in
the ‘‘From’’ header field.
match_subject(pattern)
Messages that match the regular expression pattern (string) in
the ‘‘Subject’’ header field.
match_to(pattern)
Messages that match the regular expression pattern (string) in
the ‘‘To’’ header field.
match_field(field, pattern)
Messages that match the regular expression pattern (string) in
the field (string) header field.
match_header(pattern)
Messages that match the regular expression pattern (string) in
the message header.
match_body(pattern)
Messages that match the regular expression pattern (string) in
the message body.
match_message(pattern)
Messages that match the regular expression pattern (string) in
the message.
The following method can be used to get all messages in a mailbox:
select_all()
All messages.
The following method can be used to search for messages using user
queries based on the IMAP specification (RFC 3501 Section 6.4.4):
send_query(criteria)
Searches messages by sending an IMAP search query as described in
the search criteria (string).
send_query(criteria, charset)
Searches messages by sending an IMAP search query as described in
the search criteria (string). while charset (string) indicates
to the server the character set of the strings that appear in the
query. Character sets are defined in RFC 2978 and must be
supported by the server.
Examples:
messages = myaccount.mymailbox:is_new()
messages = myaccount.mymailbox:is_recent()
messages = myaccount.mymailbox:is_larger(100000)
messages = myaccount.mymailbox:is_older(10)
messages = myaccount.mymailbox:has_flag(’MyFlag’)
messages = myaccount.mymailbox:arrived_before(’01-Jan-2007’)
messages = myaccount.mymailbox:sent_since(’01-Jan-2007’)
messages = myaccount.mymailbox:contain_subject(’test’)
messages = myaccount.mymailbox:contain_field(’Sender’, ’user@host’)
messages = myaccount.mymailbox:contain_body(’hello world’)
messages = myaccount.mymailbox:match_from(’.*(user1|user2)@host’)
messages = myaccount.mymailbox:match_message(’^[Hh]ello world!?$’)
messages = myaccount.mymailbox:select_all()
messages = myaccount.mymailbox:send_query(’ALL’, ’ISO-8859-1’)
messages = myaccount[’mymailbox’]:is_new()
messages = myaccount[’myfolder/mymailbox’]:is_recent()
PROCESSING
The following method can be used to delete messages in a mailbox:
delete_messages(messages)
Deletes the messages (table).
The following methods can be used to copy and move messages in a mailbox
at the same or different accounts. If the destination mailbox is in a
different account than the source mailbox, then the messages are
downloaded and then uploaded to the destination:
copy_messages(destination, messages)
Copies the messages contained in messages (table), to the
destination, which is a mailbox at an account.
move_messages(destination, messages)
Moves the messages contained in messages (table), to the
destination, which is a mailbox at an account.
The following methods can be used to mark messages in a mailbox:
mark_answered(messages)
Marks messages (table) as answered.
mark_deleted(messages)
Marks messages (table) for later removal.
mark_draft(messages)
Marks messages (table) as draft.
mark_flagged(messages)
Marks messages (table) for urgent/special attention.
mark_seen(messages)
Marks messages (table) as read.
unmark_answered(messages)
Unmarks messages (table) that have been marked as answered.
unmark_deleted(messages)
Unmarks messages (table) that have been marked for later removal.
unmark_draft(messages)
Unmarks messages (table) that have been marked as draft.
unmark_flagged(messages)
Unmarks messages (table) that have been marked for urgent/special
attention.
unmark_seen(messages)
Unmarks messages (table) that have been marked as read.
The following methods can be used to flag messages in a mailbox. The
standard system flags are ‘‘\Answered’’, ‘‘\Deleted’’, ‘‘\Draft’’,
‘‘\Flagged’’, ‘‘\Seen’’, while if the server supports it, new user
keywords may be defined:
add_flags(flags, messages)
Adds the flags (table that contains strings) to the messages
(table).
remove_flags(flags, messages)
Removes the flags (table that contains strings) from the messages
(table).
replace_flags(flags, messages)
Replaces the flags (table that contains strings) of the messages
(table).
Examples:
myaccount.mymailbox:delete_messages(messages)
myaccount.mymailbox:copy_messages(myaccount.othermailbox, messages)
myaccount.mymailbox:move_messages(otheraccount.mymailbox, messages)
myaccount.mymailbox:mark_seen(messages)
myaccount.mymailbox:unmark_flagged(messages)
myaccount.mymailbox:add_flags({ ’MyFlag’, ’\\Seen’ }, messages)
myaccount.mymailbox:remove_flags({ ’\\Seen’ }, messages)
myaccount[’mymailbox’]:delete_messages(messages)
myaccount[’myfolder/mymailbox’]:copy_messages(myaccount.othermailbox,
messages)
myaccount.mymailbox:move_messages(otheraccount[’myfolder/mymailbox’],
messages)
FETCHING
The following methods can be used to fetch parts of messages. The
methods return a table, which for each message contains a string, the
part that has been fetched. The downloaded messages are cached locally,
so they can be reused inside the same program session:
fetch_message(messages)
Fetches the header and body of the messages (table).
fetch_header(messages)
Fetches the header of the messages (table).
fetch_body(messages)
Fetches the body of the messages (table).
fetch_fields(fields, messages)
Fetches the header fields of the messages (table).
The following methods can be used to fetch details about the state of
messages:
fetch_flags(messages)
Fetches the flags of the messages (table). Returns a table,
which for each message contains a table of strings.
fetch_date(messages)
Fetches the internal date of the messages (table). Returns a
table which for each message contains a string.
fetch_size(messages)
Fetches the size of the messages (table). Returns a table which
for each message contains a number.
Examples:
myaccount.mymailbox:fetch_message(messages)
myaccount.mymailbox:fetch_fields({ ’from’, ’subject’ }, messages)
myaccount[’mymailbox’]:fetch_message(messages)
myaccount[’myfolder/mymailbox’]:fetch_message(messages)

FUNCTIONS

The following auxiliary functions are also available for convenience:
form_date(days)
Forms a date in ‘‘day-month-year’’ format that the system had
before the number of days (number), and returns it as a string.
get_password(prompt)
Displays the specified prompt (string), and reads a password,
while character echoing is turned off. Returns that password as
a string.
become_daemon(interval, commands)
Detaches the program from the controlling terminal and runs it in
the background as system daemon. The program will then repeatedly
poll at the specified interval (number) in seconds. Each time the
program wakes up, the commands (function) are executed.
pipe_to(command, data)
Executes the system’s command (string) and sends the data
(string) to the standard input channel of the subprocess. Returns
a number, the exit status of the child process.
pipe_from(command)
Executes the system’s command (string) and retrieves the data
from the standard output channel of the subprocess. Returns a
number, the exit status of the child process, and a string, the
output of the child process.
regex_search(pattern, string)
Implements Perl-compatible regular expressions
(http://www.pcre.org). The pattern (string) is a PCRE pattern.
The string (string) is the subject string in which the pattern is
matched against. Returns at least a boolean, that denotes if the
match was successful, and any captures which are of string type.
Examples:
date = form_date(14)
password = get_password(’Enter password: ’)
become_daemon(600, myfunction)
status = pipe_to(’mycommandline’, ’mydata’)
status, data = pipe_from(’mycommandline’)
success, capture = regex_search(’^[PpCcRrEe]: (.*)$’, ’mystring’)